Self-foaming cleansing systems

ABSTRACT

The present invention relates to a system that is self-foaming. The self-foaming system has at least two components that are maintained in separate containers. The components produce carbon dioxide when they commingle with each other upon being dispensed from their individual containers. The components are stored separately by being partitioned in separate containers or a container having a chamber for each of the components. The self-foaming system of the present invention has cleansing and cooling properties. The system is mild yet non-irritating because it cools and cleans deeply without interfering with the natural barriers of the skin.

FIELD OF THE INVENTION

The present invention relates to self-foaming systems. In particular,the invention relates to self-foaming systems having at least twocomponents that effervesce when they are dispensed and that arecleansing, cool, and refreshing to the skin.

BACKGROUND OF THE INVENTION

Typical cleanser formulations are designed to effectively andefficiently remove previously applied face powder, rouge, foundationbases, eyeshadow and lipstick. Surfactants are also particularly usefulin removing waterproof makeup. In addition, cleansers remove dirt andoil that accumulate on the skin or in the hair. To achieve this,commercial facial cleansers, usually in the form of a gel, lotion orcream, use surfactant ingredients. Further, a refreshing feeling isexperienced when the surfactant is in contact with water because itgenerates a bubbly foam. Unfortunately, many surfactants are drying tothe skin and/or are irritating to user. Because they containsurfactants, many cleansers cannot be routinely used in or in someinstances even around the eye area.

Surfactants can interfere with the natural protective lipid barrier ofthe skin. There are two sources of skin surface lipids making up thisimportant barrier: the sebaceous glands and the epidermis. Lipids are adiverse croup of compounds, comprising triglycerides, diglycerides,ceramides, free fatty acids, wax esters, cholesterol and cholesterolesters, and squalene. The quantity and composition of the skin surfacelipids differ from place to place on the body, and may to some extent berelated to the number of sebaceous glands in a given area of the skin.The condition of the skin surface lipids may also be affected by anessential fatty acid deficiency. Additionally, the lipid barrier can bediminished by exposure to harsh detergents or soaps containingsurfactants. Therefore, cleansers are desired which do not interferewith the lipid barrier of the skin, but which clean thoroughly and, feelcool and refreshing.

Another desirable characteristic of cleansing products is the refreshingfeeling derived from a cooling sensation on the skin. To achieve aphysiological cooling effect on the skin, it is known in the prior artto use, for example, menthol or other similar low volatile compounds.Other compositions used include acyclic secondary and tertiarysulphoxides and sulphones, p-menthane and its derivatives. However,these compositions have a strong odor and are not desirable for use onthe skin. Therefore, a less traditional form is needed that will providea refreshing and cooling feeling that is pleasant to use.

Consumers of cleansers not only desire a product that cleans deeply,they desire a product that “feels” like it cleans deeply. This feelingis achieved when a cleanser product is cool, refreshing and tingly orbubbly during its use. The present invention provides a self-foamingsystem that produces a cooling sensation, cleans deeply, and “feels”like it cleans deeply but does not interfere with the delicate lipidbarrier of the skin.

SUMMARY OF THE INVENTION

The present invention relates to a cosmetic or pharmaceuticalself-foaming system for application to the skin or the hair. The systemcomprises, as separate aqueous components, at least two components: anacid component and an alkali metal bicarbonate component. The acidcomponent is either an organic acid with no greater than 8 carbon atomsor an inorganic acid. Examples of acids include but are not limited tocitric acid, ascorbic acid, tartaric acid, gluconic acid, malic acid,acid potassium bitartrate, acid sodium citrate, phosphoric acid and acidphosphate and pyrophosphate salt, such as monosodium phosphate anddisodium pyrophosphate, salicylic acid, lactic acid, as well as othersalts of these acids. The bicarbonate component can be sodiumbicarbonate or potassium bicarbonate. The two components are eachcombined with a cosmetically or pharmaceutically acceptable carrier. Touse the system, the components are dispensed and applied to the surfaceto be treated, such as the skin or the hair. Upon commingling with eachother, the acid and bicarbonate components release carbon dioxide

In one embodiment, the present invention relates to a unitary packagefor dispensing the cosmetic or pharmaceutical self-foaming cleansing.The package for the cleansing system has at least two individual,separate non-communicating chambers. Each chamber holds a differentreactive component and has an opening for dispensing the components. Thenon-communicating chambers keep the components inert while they areseparate and until they are dispensed from the chambers. When thecomponents are combined as described above, they produce carbon dioxideand generate an effervescent cleansing experience. The present inventionincludes a method of cooling the skin which comprises applying aneffective amount of the cosmetic or pharmaceutical self-foaming system.

The self-foaming cleansing system is advantageous because it is gentlerto the lipid barrier of the skin than a traditional cleanser containinga large percentage of surfactants, yet the system cleans deeply and hasa tingly, bubbly and cool feel when used. The cleanser helps prevent thedevelopment of dry skin and other undesirable results that can occurwhen using, for example, a cleanser with a large amount of surfactants.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is cosmetic or pharmaceutical systems having atleast two components that commingle and effervesce upon being dispensedsimultaneously from separate containers. An important aspect of thepresent invention is its ability to provide cleansing and coolingproperties. Accordingly, the present invention includes a cleansingsystem and a method for cooling the skin which comprises applying theself-foaming system to the skin. Another feature of the presentinvention is that the effervescent property of the system occurs at aparticular time when the user applies it to the skin or the hair.

Foaming action is primarily desirable at the time the system is appliedto and during use on the skin or the hair. After the components of thesystem are dispensed from their respective containers or chambers, theyare applied to the skin or the hair where effervescence is desiredimmediately upon contact. In contrast, before applying the components ofthe system to the skin, effervescence is not necessary. Likewise, afterusing the system on the skin or the hair, effervescence is no longerneeded because use of the system is concluded and the components of thesystem are removed from the skin or the hair by rinsing or some othersimilar action. Therefore, the timing involved in creating theeffervescent property is an important aspect of the system.

Effervescence is a widely used, desirable and useful property of manycommercial products that makes a product feel tingly or bubbly.Typically, the effervescent property of these products is based on thegeneration of carbon dioxide gas. The creation of carbon dioxide gasinvolves reacting an acid with bicarbonate. Bicarbonate is a relativelycommon household product also known as baking soda. In aqueous solution,bicarbonate releases carbon dioxide gas unless it is stabilized.Generally, this reaction proceeds rapidly because the acid and thealkaline neutralize each other. As the reaction progresses towardcompletion the effervescence diminishes and eventually ends when thereaction is complete.

It is known in the prior art to use sodium bicarbonate in personal careproducts. For example, a sodium bicarbonate effervescent system is usedin a toothpaste product after overcoming challenges to make a productthat is acceptable to the user. U.S. Pat. No. 4,487,757, incorporatedherein by reference, discloses how to make a toothpaste containercontaining a baking soda toothpaste that overcomes the challenges ofwater solubility, salty taste, stability in the container, and itsappearance when dispersed. An example of a two component foaming systemis disclosed in U.S. Pat. No. 5,455,035 which provides for a surfaceactive material in a cosmetic composition by neutralizing an organicacid surfactant precursor having 10 to 20 carbon atoms, and an alkalineneutralizing agent to provide the surface active material.

An important feature of the present invention is its ability to providea self-foaming system that is substantially non-irritating. In contrastto other foaming systems, which require the use of surfactants or otherirritating agents to achieve the desired foaming property, the presentinvention achieves this by carbon dioxide generation in situ uponapplication. When use of the cleansing system is desired, the componentsare combined. The components mix together as they are poured out oftheir respective chambers and they react to create carbon dioxide gas.Accordingly, at least one of the components is an alkali metal carbonateor bicarbonate.

The alkali metal bicarbonate can be, for example, sodium carbonate,sodium bicarbonate or potassium bicarbonate. In a preferred embodiment,the bicarbonate component is dissolved in an aqueous solution. Thealkali metal bicarbonate may totally dissolved, or it may besupersaturated. Effervescence occurs only when the separate componentsof the system are combined in the presence of water. However it iswithin the scope of the present invention to utilize other solutionsincluding non-aqueous solutions (i.e., for use in anhydrous products).In the case of an anhydrous product, water can be added to produceeffervescent action or, the anhydrous product can be added to water. Forexample, the present invention may be in the form of a sachet containingthe components of the system that is added to a bath of water.

At least one of the other components reacts with the bicarbonatecomponent to yield carbon dioxide gas. This other component can be anacid having 1 to 8 carbon atoms and being water soluble. The acid can bea carboxylic acid. Specific examples of the acid component include butare not limited to citric acid, ascorbic acid, tartaric acid, lacticacid, salicylic acid, gluconic acid, malic acid, fumaric acid and saltsthereof. Examples of acid sodium, potassium, and calcium salts includebut are not limited to acid potassium tartrate, acid potassiumbitartrate, calcium phosphate, sodium aluminum phosphate, sodiumaluminum sulfate, monosodium phosphate, disodium pyrophosphate, calciumlactate, calcium sulfate, calcium phosphate, sodium aluminum phosphate,sodium aluminum sulfate, monosodium phosphate and disodiumpyrophosphate. Preferably, the acid is a citric, lactic or salicylicacid, or a combination thereof.

The acid component can also include leavening agents, such as thosedisclosed in Brose, E., et al., “Chemical Leavening Agents”, (ChemischeFabrik Budenheim Rudolf A. Octker 1996), pps. 13-24. Examples ofleavening agents can include but are not limited to acid sodium,potassium, and calcium salts of citric acid and tartaric acid, orthophosphoric acid, and pyrophosphoric acid. Other specific leaveningagents include, calcium lactate, calcium sulfate, sodium acidpyrophosphate, monocalcium phosphate monohydrate, anhydrous monocalciumphosphate, dicalcium phosphate dihydrate, sodium aluminum phosphate,sodium aluminum sulfate, acidic potassium tartrate, glucono deltalactone, citric acid, tartaric acid, fumaric acid and lactic acid.

The two reactive components can be dispensed from physically separatepackages or from a unitary package with chambers. The components ofeither type of packages can be applied simultaneously or substantiallysimultaneously to the skin, where they commingle and react. The term“substantially simultaneously” as used herein refers to application ofeach of the components within temporal proximity to one another notlonger than the stability of the initially applied component. In otherwords, there may be two steps to applying the two reactive components.In the first step, one component is applied to the skin and in thesecond step, the other component is applied over the first componentwithin a period of time less than the stability time of the firstcomponent. The components are, thus, applied substantiallysimultaneously such that commingling occurs when the second component isapplied on top of the first component. For example, one package cancontain a cosmetic composition in the form of a moisturizer containingthe acid component which is applied to the skin. The other package cancontain another cosmetic composition in the form of a foundationcontaining the bicarbonate component which is applied on top of thepreviously applied moisturizer. Commingling occurs when the foundationis applied over the layer of the moisturizer on the skin.

When the components are applied in two steps, the time of applying thesecond component and commingling it with the first component is limitedby the stability of the first component that is applied to the skin. Thestability of the first component can depend on external factors such ashumidity, temperature, and other factors as, for example, contact withmaterials or agents that alter the stability of the component or evenremove the component from the surface of the skin. However, underconditions that do not alter the stability of the first component and/ordo not cause the first component to be removed from the skin, the amountof time within which the second component can be applied to the skin andstill result in commingling with the first component sufficient to bringabout cooling and effervescence is from about 1 to about 60 minutes.

Preferably, the components of the system are dispensed from a unitarypackage. The package has at least two separate, non-communicatingchambers for containing each of the different reactive components and anopening for dispensing the components. The opening of the chamber isdesigned to permit substantial simultaneous dispensing and comminglingof the reactive components (i.e., the components merge immediately asthey flow out of their individual chambers.)

Non-communicating containment keeps the components in close proximity toone another; but, prevents them from coming into contact with oneanother until the desired time of their use. For example, thebicarbonate component is kept physically separate from the acidcomponent to prevent premature interaction. The bicarbonate component isstable and non-effervescent while it is partitioned separately from theacid component. Therefore, the components remain inert while they arecontained in separate chambers. At the desired time of use, thecomponents are dispensed from their respective chambers. As they flowout, they commingle and react with each other to create carbon dioxidegas and consequently, to create the effervescent property of the system.

The form of the package can be a tube, a bottle, an aerosol orpressurized gas activated can or other suitable container. The unitarypackage may also have multiple chambers within, if there are more thantwo components. For example, a tube can be molded to have more than onepartitioning wall inside to produce multiple chambers within the tube.

In a preferred embodiment of the present invention, the self-foamingsystem comprises an alkali metal bicarbonate component and an organicacid component having not greater than 8 carbon atoms. More preferably,the alkali metal bicarbonate of the system is sodium bicarbonate and theorganic acid is citric acid. The degree of effervescence (i.e., thelongevity and intensity) obtained when the sodium bicarbonate and thecitric acid components come into contact with each other and react,after being dispensed from their respective containers, can be adjustedby changing the ratio of these components to one another and therelative amounts of the two components present in the system.

To intensify and lengthen the duration of the reaction and consequently,the effervescent property derived from carbon dioxide generation, eachof the components of the system may be present in an amount from about0.5 to about 50 percent, by weight of each component, preferably about 1to about 20 percent, and more preferably about 1 to about 10 percent.The components are present in the system in a ratio of 1.0:0.5 to0.5:1.0 by weight of each component; more preferably 1:1. However, theratio can be adjusted according to the concentration of the components.Similarly, the cooling sensation created by the system varies inintensity and longevity in a manner comparable to that of theself-foaming action.

The degree of effervescence can also be enhanced during application tothe skin or the hair. For example, agitation such as rubbing, circulartype motion, or other similar types of action by the user duringapplication of the product augments the degree of effervescenceexperienced while applying the system to the skin or the hair. Some ofthe carbon dioxide gas produced at atmospheric pressure remains insolution and can settle in the skin or hair as it is applied. Thesephenomena not only help prolong the degree of effervescence but alsoallow the system to be used as a mousse in a nonpressurized package(i.e., the package does not require the use of propellants as used withan aerosol can).

In one embodiment of the present invention, the system is used as acleanser. The carbon dioxide generated itself has cleansing properties,and the self-foaming and cooling aspects of the reaction accomplish whatsurfactants are specifically needed for in many formulations. Thesurfactant, similarly, may be used in any amount appropriate for thechosen surfactant. However, preferably, because the surfactant is notrequired in large amounts in the present invention, the surfactant willgenerally be present in smaller quantities, in an amount of no greaterthan 20% by weight of the total composition; more preferably no greaterthan 10%. The quantity of surfactants used in the system is reduced incomparison with the quantity of surfactants used in typical foamingproducts. Typically, a foaming product uses about 40 to about 60%surfactant by weight of the total composition. But, the systems of thepresent invention provide self-foaming action using considerably lessthan that amount (i.e., about 20%). Therefore, the system of the presentinvention can reduce the quantity of surfactant needed by abouttwo-thirds to one-half of the quantity used in standard self-foamingproducts. In a preferred embodiment, the amount of surfactant added isno greater than 10% by weight of the total composition.

The surfactant may be of any type. In the event that it is desired toinclude a surfactant in the system, the type of surfactant incorporatedin the formulation will depend on its intended purpose. For example,surfactants may be used to assist in wetting the skin or the hair. Theproperties of surfactants may also aid in promoting the reaction betweenthe bicarbonate and the acid components thereby increasing theeffervescence of the product. The type of surfactant selected will alsobe one which does not interfere with the production of carbon dioxidegas. Additional surfactants may be included in any or all of thecomponents of the system. However, selection is further limited by thecompatibility of a given surfactant with the component into which it isincorporated. Accordingly, the surfactants employed may be any that aretraditionally used for cosmetic or pharmaceutical purposes, and may beselected from nonionic, anionic, cationic, amphoteric surfactants, ormixtures thereof, the identities of which are well known to thoseskilled in the art. Preferably, however, the surfactant is nonionic oranionic. Further, if the system is intended for use in close proximityto the eye area or other sensitive areas, it is preferred that thesurfactant be a mild surfactant, such as LIPO-PEG-2DL or disodiumcocoamphodiacetate (Miranol).

Each of the components can be formulated with a variety of cosmeticallyand/or pharmaceutically acceptable carriers. The term “pharmaceuticallyor cosmetically acceptable carrier” refers to a vehicle, for eitherpharmaceutical or cosmetic use, which vehicle delivers the activecomponents to the intended target and which will not cause harm tohumans or other recipient organisms. As used herein, “pharmaceutical” or“cosmetic” will be understood to encompass both human and animalpharmaceuticals or cosmetics. Useful carriers include, for example,water, acetone, ethanol, ethylene glycol, propylene glycol,butane-1,3-diol, isopropyl myristate, isopropyl palmitate, or mineraloil. It will be apparent to the skilled artisan that the selectedcarrier must be compatible and relatively inert with respect to thereactive components. Methodology and components for formulation ofcosmetic and pharmaceutical compositions are well known, and can befound, for example, in Remington's Pharmaceutical Sciences, EighteenthEdition, A. R. Gennaro, Ed., Mack Publishing Co., Easton, Pa., 1990.Further, the carrier may be in any form appropriate to the mode ofdelivery, for example, solutions, colloidal dispersions, emulsions(oil-in-water or water-in-oil), suspensions, creams, lotions, gels,foams, mousses, sprays, slurries and the like.

Other potentially useful additions to the self-foaming system includeemollients, humectants, fragrances, preservatives, and buffers. Suchmaterials are routinely used in cosmetic products, and listings ofappropriate materials can be found, for example in the InternationalCosmetic Ingredients Handbook, Third Edition, 1996 (“CTFA”).

The self-foaming systems of the present invention are useful in productsfor the skin or the hair such as cleansers, conditioners, suncareproducts, makeup products, and the like. More specific examples includeshampoos or rinsing products. When the system is used in a rinsingproduct, it can be applied before or after shampooing, before or afterdyeing or bleaching, before or after permanent waving orhair-straightening, or it can be applied after using a hairdressing, ahair dyeing or bleaching product, or a conditioning or hair-setting gelthat is temporarily used on the hair. Yet another form that the systemcan take is that of a shaving gel.

In one embodiment, however, the system is used primarily for its coolingeffects, and not as a cleanser. For example, the system can beadvantageously used as the base of a foundation or sun-care product.These types of products, when applied in hot and/or humid weatherconditions, can feel uncomfortable on the skin. The application of thesystem under such conditions will provide a cooling effect, in additionto the other intended effect of the product and avoid some of thediscomfort often associated with more traditional products of this type.When the cooling effect is the primary intention of the system, awater-in-silicone combination is preferred.

In a particularly preferred embodiment, however, the system is used forremoving dirt, oil, makeup, and other impurities from the skin or thehair. For example, the systems can be used in a cleanser or tonerproduct for the face or in a product for application to the body. Asalready noted, because of the ability to effervesce by means of carbondioxide gas generation, the self-foaming systems are mild and do notinterfere with the natural protective lipid barrier of the skin. Inaddition, carbon dioxide generation augments the cooling and cleansingproperties of the system.

In addition, the systems can be used for delivery of cosmetic orpharmaceutical topically therapeutic active agents to the skin for thetreatment and/or amelioration of various skin conditions. Accordingly,the self-foaming systems of the present invention may also compriseuseful active ingredients, for the purposes of treating both the skinand the hair. Useful active ingredients include, but are not limited toantioxidants, antimicrobials, sunscreens, analgesics, anesthetics,anti-acne agents, antidandruff agents, antidermatitis agents,antipruritic agents, anti-inflammatory agents, antihyperkeratolyticagents, anti-dry skin agents, antiperspirants, antipsoriatic agents,antiseborrheic agents, hair conditioners and hair treatment agents,antiaging agents, antiwrinkle agents, antihistamine agents, skinlightening agents, depigmenting agents, wound-healing agents, vitamins,corticosteroids, tanning agents, or hormones. The selection of theactive in the formulation is determined by its solubility and/orstability in either oil or water.

The present invention also includes a method of producing the coolingsensation when an effective amount of the components of the system aredispensed and applied to the skin or the hair. When combined withappropriate additional components, the resulting self-foaming systemssuccessfully cool skin surfaces, including around the eyes and lips.Moreover, they clean the skin and remove transfer-resistant cosmetics.All this is achieved while remaining gentle and substantiallynon-irritating to the user. The cooling effect may also be, in somecases, enhanced by combining the components of the system with anadditional cooling agent, for example, menthol. If an additional coolingagent is used, it is present in an amount of no greater than 5 percentof the weight of the total composition.

The invention is further illustrated in the following non-limitingexamples:

EXAMPLES

1. The following illustrates a formulation of the present invention:

Component 1 Component 2 Material (% by weight) (% by weight) DeionizedWater 90 90 Disodium EDTA 0.05 0.05 Glycereth-26 2 2 Methyl Gluceth 2 2Polaxamer 184 0.4 0.4 Potassium Sorbate 0.1 0.1 Fragrance 0.08 0.08Menthol crystals 0.02 0.02 Polysorbate 20 0.15 0.15 PPG-5-Ceteth-20 0.20.2 PEG-120 Jojoba Acid 0.2 0.2 and Alcohol Sodium Hyaluronate 0.1 0.1Sodium bicarbonate 4.7 Disodium 4.7 pyrophosphate

The constituents of each component, i.e., Component 1 and Component 2,are added until they are dissolved using a propeller mixer.

What we claim is:
 1. A method of cleansing the skin or the hair whichcomprises applying an effective amount of a cosmetic or pharmaceuticalliquid self-foaming system comprising, as separate aqueous elements, analkali metal bicarbonate component and an acid component, said acidcomponent being selected from the group consisting of an organic acidhaving a number of carbon atoms not greater than 8 and an inorganicacid, each of said components being contained in a cosmetically and/orpharmaceutically acceptable carrier, said components, when substantiallysimultaneously dispensed and commingled, reacting with one another torelease carbon dioxide.
 2. A method of cooling the skin which comprisesapplying an effective amount of a cosmetic or pharmaceutical liquidself-foaming system comprising, as separate aqueous elements, an alkalimetal bicarbonate component and an acid component, said acid componentbeing selected from the group consisting of an organic acid having anumber of carbon atoms not greater than 8 and an inorganic acid, each ofsaid components being contained in a cosmetically and/orpharmaceutically acceptable carrier, said components, when substantiallysimultaneously dispensed and commingled, reacting with one another torelease carbon dioxide.
 3. A unitary package for dispensing a cosmeticor pharmaceutical liquid self-foaming system, said package containing atleast two separate, non-communicating chambers and at least two reactiveflowable components, at least one of said reactive components being anacid in an aqueous solution of at least 80 percent, said acid beingselected from the group consisting of an organic acid having a number ofcarbon atoms not greater than 8 and an inorganic acid, at least one ofsaid reactive components being an alkali metal bicarbonate in an aqueoussolution of at least 80 percent, each of said chambers containing adifferent reactive component and having an opening for dispensing saidcomponent, wherein said components are capable of reacting with eachother when substantially simultaneously dispensed and commingled toproduce carbon dioxide, but which remain inert when contained withinsaid separate chambers.
 4. The method of claim 1 wherein the alkalimetal bicarbonate is a sodium bicarbonate.
 5. The method of claim 1wherein the acid is organic.
 6. The method of claim 5 wherein the acidis citric acid.
 7. The method of claim 1 wherein the acid is inorganic.8. The method of claim 7 wherein the acid is selected from the groupconsisting of pyrophosphoric acid, phosphoric acid, and sulfuric acid,and salts thereof.
 9. The method of claim 8 wherein the salt is calciumsulfate, calcium phosphate, sodium aluminum phosphate, sodium aluminumsulfate, monosodium phosphate and disodium pyrophosphate.
 10. The methodof claim 1 wherein the acid is a leavening agent.
 11. The method ofclaim 1 wherein the liquid self-foaming system is a toner.
 12. Themethod of claim 2 wherein the liquid self-foaming system is a toner.